Nav: Home

Safe thresholds for antibiotics in sewage needed to help combat antibiotic resistance

September 03, 2020

New research reveals current understanding of safe antibiotic levels in rivers may not prevent evolution of antibiotic resistance and fully protect human health. The study suggests the need to introduce thresholds to help fight the spread of resistant bacteria.

Around 70 per cent of the antibiotics we take as medicine end up in the natural environment, through flushed waste and discarded medicines, among other sources. These antibiotics interact with bacteria that are also present in the water, which can evolve resistance within these environments. The bacteria can then transfer resistance to human-associated bacteria, meaning antibiotics are less likely to work.

Antibiotic resistance is recognised by the World Health Organisation as one of the greatest health threats of our time. By 2050, up to 10 million deaths each year could be caused by antibiotics, and other antimicrobial drugs, no longer working to treat common diseases, including respiratory tract, sexually transmitted and urinary tract infections. The threat of resistance could also increase the risk of contracting infection after basic surgical procedures.

To prevent the situation being worsened via evolution of resistance in aquatic environments, a lot of research has attempted to determine safe concentrations of antibiotics in waste water that do not contribute to resistance. However, new research by the University of Exeter and AstraZeneca, published in Communications Biology, indicates that current thresholds may not be sufficient to prevent evolution of resistance.

The research team conducted laboratory experiments testing five antibiotics grouped within three commonly-used classes of antibiotics - macrolide (azithromycin, clarithromycin and erythromycin) fluoroquinolone (ciprofloxacin) and tetracycline. The macrolides and ciprofloxacin were included on the European Commission Water Framework Directive's Priority Substances Watch List in 2018, due to concerns about their toxicity to aquatic life. The team investigated the lowest concentrations at which resistance to antibiotics evolved in complex communities of bacteria present in wastewater. The team found that fluoroquinolone concentrations similar to those found in the environment did drive increased antibiotic resistance, whereas macrolides did not, confirming the need to set thresholds specific to the type of antibiotic.

Furthermore, the team found that resistant bacteria persisted in water at concentrations below the current threshold used to determine when mitigation strategies may need to be implemented. This presents a greater risk of human exposure to antibiotic resistant bacteria in the environment, and a greater chance that increased resistance could evolve over time.

Dr Isobel Stanton, of the University of Exeter, said: "Antibiotic resistance is a grave international threat to life. While much attention has focussed around reducing use in clinical environments, we also need to urgently curb evolution and transmission of bacteria that are resistant to antibiotics through the natural environment. Our research indicates that current thresholds proposed may still be too high, and may not completely remove the risk posed by antibiotics present in aquatic environments."

Professor Will Gaze, of the University of Exeter, said: "Our work has helped to increase understanding of the extent to which rivers, streams and oceans contribute to the spread of antibiotic resistance in humans. We now need action to ensure waste water contains safe levels of antibiotics, to slow the increase in antibiotic resistance which threatens society."
-end-
The research was supported by BBSRC, AstraZeneca and NERC. The paper is entitled 'Evolution of antibiotic resistance at low antibiotic concentrations including selection below the minimal selective concentration'.

University of Exeter

Related Science Articles:

75 science societies urge the education department to base Title IX sexual harassment regulations on evidence and science
The American Educational Research Association (AERA) and the American Association for the Advancement of Science (AAAS) today led 75 scientific societies in submitting comments on the US Department of Education's proposed changes to Title IX regulations.
Science/Science Careers' survey ranks top biotech, biopharma, and pharma employers
The Science and Science Careers' 2018 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.
Science in the palm of your hand: How citizen science transforms passive learners
Citizen science projects can engage even children who previously were not interested in science.
Applied science may yield more translational research publications than basic science
While translational research can happen at any stage of the research process, a recent investigation of behavioral and social science research awards granted by the NIH between 2008 and 2014 revealed that applied science yielded a higher volume of translational research publications than basic science, according to a study published May 9, 2018 in the open-access journal PLOS ONE by Xueying Han from the Science and Technology Policy Institute, USA, and colleagues.
Prominent academics, including Salk's Thomas Albright, call for more science in forensic science
Six scientists who recently served on the National Commission on Forensic Science are calling on the scientific community at large to advocate for increased research and financial support of forensic science as well as the introduction of empirical testing requirements to ensure the validity of outcomes.
World Science Forum 2017 Jordan issues Science for Peace Declaration
On behalf of the coordinating organizations responsible for delivering the World Science Forum Jordan, the concluding Science for Peace Declaration issued at the Dead Sea represents a global call for action to science and society to build a future that promises greater equality, security and opportunity for all, and in which science plays an increasingly prominent role as an enabler of fair and sustainable development.
PETA science group promotes animal-free science at society of toxicology conference
The PETA International Science Consortium Ltd. is presenting two posters on animal-free methods for testing inhalation toxicity at the 56th annual Society of Toxicology (SOT) meeting March 12 to 16, 2017, in Baltimore, Maryland.
Citizen Science in the Digital Age: Rhetoric, Science and Public Engagement
James Wynn's timely investigation highlights scientific studies grounded in publicly gathered data and probes the rhetoric these studies employ.
Science/Science Careers' survey ranks top biotech, pharma, and biopharma employers
The Science and Science Careers' 2016 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.
Three natural science professors win TJ Park Science Fellowship
Professor Jung-Min Kee (Department of Chemistry, UNIST), Professor Kyudong Choi (Department of Mathematical Sciences, UNIST), and Professor Kwanpyo Kim (Department of Physics, UNIST) are the recipients of the Cheong-Am (TJ Park) Science Fellowship of the year 2016.
More Science News and Science Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.